In general, a motor is an apparatus for obtaining rotation power by converting electrical energy into mechanical energy. Such an electromotor is chiefly classified into an AC motor and a DC motor according to the type of a power supply supplied thereto. From among them, the AC motor is widely used in order to drive home appliances.
The motor includes a stator and a rotor. The motor is rotated by torque which is generated in the rotor by a rotating magnetic field generated when an AC current flows through armature windings having coils wound thereon.
In general, the motor is classified into a core type (or a radial type) having a cup (cylinder) structure and a coreless type (or an axial type).
The radial type motor has a structure in which magnetic circuits are symmetrical around its shaft in the radial direction. The radial type motor is advantageous in that axial vibration noise is small, torque is great, and efficiency is high, but is disadvantageous in that windings are difficult, the stator and the rotor have a complicate structure, and thinning is difficult.
Various forms of the axial motors have been developed in view of the above problems. However, the existing axial motors are disadvantageous in that they are not appropriate for mass production because the core teeth and the yoke are integrally formed and they have a complicate structure in which the core teeth are coupled to the yoke even in a structure in which the core teeth and the yoke are separated from each other.